Do you believe that it is rude to tell a room full of obnoxiously loud people to shut up?

I just wanted to get peoples opinion's on this so that I could decide for myself if shouting "Shut up!" at the top of my lungs to my homeroom was considered rude by them or not.

I was trying to listen to the announcements(specifically for Prom Court, because I wanted to know), and our teacher was trying to get everyone's attention. He kept saying, "Are you guys listening? They're announcing the Prom Court! Hey, are you guys hearing this?" and they repeatedly ignored him. They were practically screaming at the top of their lungs, and I was so irritated at that point that I turned my head to that specific side of the room and told them(very loudly), to shut up. I've gotten some nasty looks from some of them since that transpired, and I feel like they think I was the one being rude.